Defending with an 8 card suit – solution?

I  guess the first question to ask is what does the double show? Is it a strong preference to defend, with a good/wasted diamond holding, or can be made with a hand like AQxxx x xxx AQxx? My discussion with other peers is not conclusive. Personally, I think pass should say ‘I don’t have anything to say at this point’, while a bid or double is highly suggestive.

The winner on this hand was passing. Partner was 5-5 in spades and diamonds. RHO had KJ9xx in hearts.

My partner Marielle Brentnall found a pass at the table! This is just one hand, but I find this type of situation both interesting and important.